Who has the authority from emergency services?

The practice probably varies in each case, but TV stories often depict rivalry between police and fire. I suspect the answer lies with the court when there is a dispute.

I have never thought about it, but assume it would be on a case by case basis. There’s something missing from that news report. WHY did the CHP officer want the firetruck moved when people there were obviously injured??? HOW did the fireman refuse to move the truck??? Was he belligerent or combative??? It will be interesting to hear how this ends!!!